| 1 | Exocrine pancreatic function assessed by secretin cholangio-Wirsung magnetic resonance imaging显示文摘BACKGROUND:Magnetic resonance cholangiopancreato-graphy (MRCP) is useful to assess exocrine pancreatic function by combining rapid imaging acquisition with the administration of secretin, a gastrointestinal hormone that stimulates the secretion of bile and pancreatic juice. However, extensive data on this method are lacking. This study aimed to determine whether MRCP with secretin administration is able to simultaneously detect alterations of both the pancreatic ducts and exocrine pancreatic function. METHODS:All subjects older than 18 years who underwent magnetic resonance imaging (MRI) and cholangio-Wirsung magnetic resonance imaging (CWMRI) for suspicion of benign or malignant pancreatic diseases from January 2006 to December 2006 were enrolled in the study. MRI and CWMRI were carried out using a dedicated apparatus. RESULTS:Eighty-seven patients (46 males, 41 females, mean age 59.7±14.6, range 27-87 years) were enrolled. Of the 87 patients, 39 had a normal pancreas on imaging, 20 had an intrapapillary mucinous tumor (IPMT), and the rest had chronic pancreatitis (7), serous cystadenoma (6), a previous attack of acute biliary pancreatitis (5), congenital ductal abnormalities (5), mucinous cystadenoma (3), previous pancreatic head resection for autoimmune pancreatitis (1), or cholangiocarcinoma (1). Morphologically, we found two pseudocysts (one of the 7 patients with chronic pancreatitis, and one of the 5 patients after an attack of acute pancreatitis;the latter pseudocyst communicated with the main pancreatic duct). Calcifications were found in 3 of the 7 patients with chronic pancreatitis. All patients with IPMT and mucinous cystadenoma and 3 patients with serous cystadenoma were histologically confirmed. The remaining patients were followed up adequately to confirm the diagnosis by imaging. According to the Matos criteria, 73 patients (83.9%) were of grade 3, 8 grade 2, 4 grade 1, and 2 grade 0. The only pancreatic diseases which impaired the exocrine pancreatic secretion stimulated by secretin were chronic pancreatitis (57.1% of the patients, grade 0-1) and the IPMT mixed type in 2 of the 4 patients was grade 1. CONCLUSION:Secretin MRCP is a useful technique to simultaneously detect the presence of alterations of the pancreatic ducts and exocrine pancreatic function. | Lucia Calculli Raffaele Pezzilli Marta Fiscaletti Riccardo Casadei Carla Brindisi Giampaolo Gavelli | 2008 | Hepatobiliary & Pancreatic Diseases International2008，7，2： | 5 |
| 4 | Evolution of turbulent boundary layer over a three-dimensional bump显示文摘A bump is typically used in the inlet system of an aircraft engine to compress the incoming airflow and to reduce boundary layer thickness developed over fuselage.In this work,the turbulent flow over a three-dimensional bump is experimentally studied.The bump model is mounted in a closed return wind tunnel operated at the nominal velocity 10 m/s,corresponding to a friction Reynolds number of 2300.The flow field upstream the bump,along the bump centerline and at two different spanwise planes is measured with Particle Image Velocimetry(PIV).It is observed that a favorable pressure gradient develops until the suction peak of the bump,and that the average turbulence intensity within boundary layer is attenuated due to this favorable pressure gradient.The boundary layer thickness identified by examining profiles of streamwise velocity decreases significantly along the bump.The wall-normal position of the Turbulent/Non-Turbulent Interface(TNTI)identified with the vorticity criterion is also observed to decrease along the bump.When studying the behavior of the boundary layer thickness at different spanwise positions,we found that it tends to be larger in planes away from the centreline,which suggests that the bump diverts the flow. | Jun LIU Daniele FISCALETTI Huacheng YUAN | 2022 | Chinese Journal of Aeronautics2022，35，6： | 0 |
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